Surface treatment and items having treated surface

ABSTRACT

A method of applying a bittering agent to a substrate provided by an item which it is desired to impregnate in order to prevent, for example, chewing of the item, is disclosed. The method comprises the steps of: applying a first coating layer to the substrate, the first coating layer being of a substance that can be treated to acquire a hardened state; applying a bittering agent to the first layer; and treating the first coating layer thereby to generate the hardened state.

BACKGROUND TO THE INVENTION

1. Field of the Invention

The present invention relates to the treatment of items to make themunpleasant to taste. One example of the use of the present invention,but by no means the only such example, is the treatment of items whichhave common use in domestic circumstances such as buttons, zips,television remote controls, computer mice. Items such as this, theircommon usage domestically notwithstanding, might, if ingested becomedangerous, particularly to small children.

2. Description of Related Art

Typically, such items are rendered unpleasant to the taste as a resultof treatment with a bittering agent. Such agents are known per se andcan be applied, as a lacquer or varnish to, for example, fingernails. Itis also known to apply such agents to children's toys, for example,either by applying the agent as a ‘top layer’ to the item, or by mixingthe agent with an epoxy, acrylic or water-based coating which is thenapplied to the surface of the item. It has been found that, by usingthis method, where the agent is mixed with either a water-based, epoxyor acrylic coating, the effectiveness of the bittering agent issignificantly reduced and, accordingly, relatively large quantities ofthe agent are then required in order to produce the requisitebitterness. This, in turn, has a negative impact upon the security (i.e.safety) of the coating.

SUMMARY OF INVENTION

A first aspect of the present invention provides an alternative methodof applying a bittering agent to coat items in order to impart anundesirable, bitter taste to them. According to a first aspect of thepresent invention there is provided a method of applying a bitteringagent to a substrate provided by an item which it is desired toimpregnate in order to prevent, for example, chewing of the item, themethod comprising the steps of: applying a first coating layer to thesubstrate, the first coating layer being of a substance that can betreated to acquire a hardened state; applying a bittering agent to thefirst layer; and treating the first coating layer thereby to generatethe hardened state.

A further aspect of the present invention provides an item such as a zipslider impregnated with a bittering agent. According to an embodiment ofthe present invention there is provided an item comprising a substrateto which a first coating is applied, the first coating being a materialwhich has been treated to become hardened, and the first coating beingimpregnated with a bittering agent.

Embodiments of the present invention will now be described, by way ofexample, and with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flow chart illustrating an embodiment of method according tothe present invention;

FIG. 2 is a schematic representation of an apparatus used in the methodillustrated in FIG. 1

FIG. 3 is a section through the surface of an item treated with themethod of FIG. 1;

FIG. 4 is a perspective view of a zip slider according to an embodimentof the present invention

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, the first step in the process is the step 10 ofloading parts to be coated into a hot barrel spraying apparatus. In thepresent example, the parts or items to be coated are parts of a zip,such as a slider and a pull tab for a zip slider (whether in conjunctionwith the slider or separately or on its own), though a very wide rangeof items finds use in the present method. The apparatus is illustratedschematically in FIG. 2 and includes a barrel 200, mounted for rotationrelative to a base 202. The barrel 200 includes a single nozzle orplurality of nozzles 204, each of which is adapted to emit a fine sprayof a substance with which the items are to be coated. The precise natureof the coating to be applied to the items will depend upon the uses towhich they are to be put. A typical coating according to embodiments ofthe present invention is of a kind that, although applied in thismanner, is subsequently capable of acquiring a hardened state, such as avitrified state or a state equivalent to that. One example of a group ofsuch coatings are those that can be cured to acquire the aforementionedhardened state, where curing is achieved, for example, by theapplication of heat, suitable chemical additives, the application ofultra-violet light or other radiation, the application of electron beamsor any other suitable manner.

In the present example the coating is a coat of epoxy resin coating(paint), though in alternative embodiments the coating could equally beof another suitable material, such as a clear epoxy or acrylic lacquercoating for example, or enamel. In order to provide the appropriateconditions under which to apply that coating, the interior of the barrel200 is heated by a suitable heating apparatus (not shown). The barrelthen rotates during the heating process to ensure the provision of asuniform a coating to the items as possible.

The items are then rotated and coated within the barrel 200, at step 20,for a period of time sufficient to apply to them a coat of the requisitethickness. Optionally, this process may be repeated a sufficient numberof times in order for the items to have the required number of coatsapplied to them. Hot barrel spraying is, however, only one method ofapplying a coating and other suitable methods may be employed.Ordinarily, at this stage in a coating process, the items will then becured by heating to the same or a significantly higher temperature, forexample in suitable kiln or retort.

According to the present embodiment, however, at this point, shortlyafter completion of the coating step and, preferably immediately thecoating step is completed, at step 30, a coating of the bittering agentis then applied to the items. In the present embodiment, the bitteringagents is sucrose octa-acetate in a concentration of in the range 20-50ppm. Other bittering agents, such as denatonium benzoate or denatoniumsaccharide may be employed; or any other suitable bittering agent whichis not harmful to ingest.

The addition of the bittering agent may also be performed in the hotbarrel apparatus. Alternatively, the coating may be applied by anothersuitable method consistent with the nature of the bittering agent andthe uncured coating to which the bittering agent is to be applied. Thebittering agent is sprayed onto the uncured coated materials for 1 to 2minutes, with in the present example in which the item is a zip slider,around 2-3 ml of bittering agent are being used per load/batch. Thisstep will result in the coating being impregnated with the bitteringagent.

At step 40, the items are then cured in the hot barrel for a period oftime at a given temperature suitable to the coating applied or placed ina kiln or other suitable heating retort in order to cure the coatingsfor a suitable period of time and at a suitable temperature havingregard to the nature of the item. For example, in the case of EpoxyCoating a 10 minute cure cycle is used in the hot barrel, with a halfrotation every 1 minute and then this is followed by a 30 minutes curecycle at 100° C. in a kiln.

Referring to FIG. 3, the result of the process described above is that,to the metal substrate (in this example aluminium of a zip slider, andtherefore may also comprise an upper layer of aluminium oxide) 300,there is then applied an enamel coating 310 and the upper layer 320 ofthis is covered with a bittering agent. It has been found that, in theabove-described embodiment, as the bittering agent layer 320 is applieddirectly to the softened uncured enamel coating layer 310, so thisallows the bittering agent layer 320 to impregnate the enamel surface,but not distribute through the full coating and so only a small amountis needed for this to be effective, as it seeps into the top surface ofthe coating only. In addition, the coating is more durable to washingand so the bittering agent properties will also remain effective as itis embedded in the surface of the coating.

This is also possible with plated components that are coated with clearepoxy/water based or acrylic lacquers and then sprayed with bitteringagents before the coating is fully cured.

The bittering agent can also be mixed with other additives at the sametime i.e. a mixture of wax and bittering agent can be applied at thesame time to give both lubrication and bitter taste at the same time.

The process of the present invention finds application in the treatmentof items that, for example, for safety reasons, it is undesirable for achild to chew, such as a zip slider, for example but also findsapplicability in connection with a cornucopia of other items includingbuttons and other garment fasteners or parts thereof, computer mice,remote controls, the tops of bottles (such as those containing harmfulsubstances), pen tops or (which may be useful to break a habit ofchewing, even in grown ups).

1. A method of applying a bittering agent to a substrate provided by anitem which it is desired to impregnate in order to deter oral ingestionof the item, the method comprising the steps of: applying a firstcoating layer to the substrate, the first coating layer being of asubstance that can be treated to acquire a hardened state; applying abittering agent to the first layer; and treating the first coating layerthereby to generate the hardened state.
 2. A method according to claim 1wherein the first coating layer is made of a substance that can be curedto create its hardened state.
 3. A method according to claim 1 whereinthe bittering agent is not harmful for humans to ingest orally.
 4. Amethod according to claim 3 wherein the bittering agent is selected fromthe group consisting of sucrose octa-acetate, denatonium benzoate, anddenatonium saccharide.
 5. A method according to claim 1 wherein thesubstrate is a metal.
 6. A method according to claim 5 wherein thesubstrate includes a metal oxide.
 7. A method according to claim 1wherein the item is one a zip slider or a pull tab for a zip slider. 8.An item having a substrate to which a first coating is applied, thefirst coating being a material which has been treated to becomehardened, and the first coating being impregnated with a bitteringagent.
 9. An item according to claim 8 wherein the first coating is amaterial that has been hardened by curing.
 10. An item according toclaim 9 wherein the first coating includes one of expoxy resin orenamel.
 11. An item according to any one of claims 8 wherein thebittering agent is a substance which is not harmful for humans to ingestorally.
 12. An item according to any one of claim 11 wherein thebittering agent is selected from a group consisting of: sucroseocta-acetate, denatonium benzoate, and denatonium saccharide.
 13. Anitem according to any one of claim 8 wherein the item is a zip slider ora pull tab for a zip slider.